HP switch 2600 serial port speed-duplex configuration

Hi, HP switch expert,

We are supporting Patriot Coal company network. We see several HP switches 2626, 2524 and 2650 having 10/half and 100/half links betweens. We changed the speed-duplex to 100/full but lost the switch connection immediately. Need to reboot the switch to gain network connection. Bu reading switch guideline and got feeling that any hp switch port is defaulted to auto. Other end has to be auto setting. Otherwise, the switch port only can sense 10/half and 100/half. Is this true? How can I configure a switch port to 100/full?

"Because the Series 2600 Switches behave in this way (in compliance withthe IEEE 802.3 standard), if a device connected to the switch has a fixedconfiguration at full duplex, the device will not connect correctly to theswitch. The result will be high error rates and very inefficient communicationsbetween the switch and the device.Ensure all devices connected to the Series 2600 Switches are configuredto auto negotiate, or are configured to connect at half duplex"

Re: HP switch 2600 serial port speed-duplex configuration

When both sides of the link are set to autoneg, they will "negotiate"the duplex setting and select full-duplex if both sides can dofull-duplex.

If one side is hardcoded and not using autoneg, the autoneg processwill "fail" and the side trying to autoneg is required by spec to usehalf-duplex mode.

If one side is using half-duplex, and the other is using full-duplex,sorrow and woe is the usual result.

So, the following table shows what will happen given various settingson each side:

Auto Half Full

Auto Happiness Lucky Sorrow

Half Lucky Happiness Sorrow

Full Sorrow Sorrow Happiness

Happiness means that there is a good shot of everything going well.Lucky means that things will likely go well, but not because you didanything correctly :) Sorrow means that there _will_ be a duplexmis-match.

When there is a duplex mismatch, on the side running half-duplex youwill see various errors and probably a number of _LATE_ collisions("normal" collisions don't count here). On the side runningfull-duplex you will see things like FCS errors. Note that thoseerrors are not necessarily conclusive, they are simply indicators.

Further, it is important to keep in mind that a "clean" ping (or thelike - eg "linkloop" or default netperf TCP_RR) test result isinconclusive here - a duplex mismatch causes lost traffic _only_ whenboth sides of the link try to speak at the same time. A typical pingtest, being synchronous, one at a time request/response, never triesto have both sides talking at the same time.

Finally, when/if you migrate to 1000Base-T, everything has to be setto auto-neg anyway.